A Long Term Evolution (LTE) project is mainly directed to the mobile communication system that the 3rd Generation Partnership Project (3GPP) Organization is preparing to enhance in the next ten years. In current LTE system, a base station performs centralized scheduling of all uplink transmissions from different terminals to improve channel utilization efficiency. The uplink dynamic scheduling includes the following steps.
Step 1: A terminal sends uplink scheduling reports, including the most important report, that is, a Buffer Status Report (BSR), and further including Power Headroom report etc, to a base station corresponding to timing or event triggering.
Step 2: The base station schedules resources for the terminals according to a certain policy based on available resources and uplink scheduling information of all terminals, and generates an authorization message for terminal uplink transmissions.
Step 3: The terminal sends the authorization message to the terminal.
Step 4: The terminal sends data and controls information according to the authorization message.
LTE system has three types of BSR according to different processing methods: Regular BSR, Periodic BSR and Padding BSR. In application, if the terminal triggers the sending of BSR and does not send the BSR to the network by utilizing uplink resources, the status of BSR is marked as pending.
If the data lately received by the buffer has a higher priority than the to-be-sent data in the buffer, or the service cell serving for the terminal has changed, the sending of Regular BSR would be triggered. At this time, if there are uplink resources available for sending, Regular BSR is generated and sent; if no uplink resources, but there are SR-PUCCH resources configured at the network, the terminal does not generate Regular BSR but marks the current status of BSR as pending and sends Scheduling Request (SR) by using SR-PUCCH resources; if there are no uplink resources and SR-PUCCH resources, the terminal does not generate Regular BSR but marks the current status of BSR as pending and sends SR by using Random Access Channel, RACH resources; when uplink resources are available for sending Regular BSR, the terminal generates and sends Regular BSR.
If the periodic timer configured in the terminal times out, the sending of Periodic BSR is triggered. At this time, if there are uplink resources for sending BSR, the terminal generates and sends the Periodic BSR; if there are no uplink resources for sending BSR, the terminal does not generate Periodic BSR but marks the current status of BSR as pending, waits for uplink resources for sending BSR and generates and sends Periodic BSR only when obtaining the uplink resources for sending Periodic BSR.
If there is still one BSR available after all to-be-sent data of the terminal is padded into the obtained uplink resources, the sending of a Padding BSR is triggered and, at this time, the terminal generates a Padding BSR and sends it as part of the uplink resources which have not been padded full.
However, in existing technical proposals, at a certain moment, if the sum of the BSR qualified for triggering the sending and the BSR marked as pending is greater than one, it may result in resource waste or system error and affect the resource utilization efficiency or system stability.